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焙烧温度对“软-硬”模板法制备的Pd/Ce0.65Zr0.35O2三效催化性能的影响 认领 引用
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作者 黄利华 陈耀强 《无机化学学报》 SCIE CAS CSCD 北大核心 2020年第11期2145-2156,共12页
采用“软-硬”模板法制备了具有高热稳定性的Ce0.65Zr0.35O2(CeZr)。考察了制备过程中焙烧温度对Ce0.65Zr0.35O2及其负载的单Pd三效催化剂(TWC)性能的影响。对样品进行了X射线衍射、比表面、拉曼光谱、X射线光电子能谱、储氧性能和H2程... 采用“软-硬”模板法制备了具有高热稳定性的Ce0.65Zr0.35O2(CeZr)。考察了制备过程中焙烧温度对Ce0.65Zr0.35O2及其负载的单Pd三效催化剂(TWC)性能的影响。对样品进行了X射线衍射、比表面、拉曼光谱、X射线光电子能谱、储氧性能和H2程序升温还原性能测试。结果表明:焙烧温度显著影响催化剂的结构和性能。随着焙烧温度的增加,Ce0.65Zr0.35O2的比表面下降,但在1000℃焙烧的样品比表面为61 m2·g-1,显著高于同温度下直接在空气中焙烧的样品。由于高温导致了物相重组,Ce0.65Zr0.35O2的储氧量和还原性能随着焙烧温度的增加而提升。由于高温烧结导致Pd分散性的下降,其负载的催化剂的还原性能随着焙烧温度的增加而下降,从而最终导致催化剂活性的降低。但在“软-硬”模板法中1000℃焙烧的样品负载的催化剂依然显示出很好的三效催化性能,该催化剂上C3H8、CO和NO的起燃温度分别为274、175和133℃,显著低于同温度下空气中直接焙烧的样品负载的催化剂。催化剂的氧化还原性能和Pd的分散性是影响催化活性的主要因素。 展开更多
关键词 Ce0.65Zr0.35O2 高热稳定性 催化性能
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钾改性Mn/Ce0.65Zr0.35O2催化剂催化氧化甲苯 认领 引用 被引量:3
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作者 赖潇潇 冯洁 +3 位作者 周晓英 侯忠燕 林涛 陈耀强 《物理化学学报》 SCIE CAS CSCD 北大核心 2020年第8期35-44,共10页
碱金属作为助剂,能够调变催化剂的电子和结构性能,从而改善催化剂的活性。本工作中,我们研究了碱金属K的添加对Mn Ox/Ce0.65Zr0.35O2催化剂氧化甲苯的性能影响。结果表明,掺杂碱金属K可以明显提高催化剂的催化活性;当K与Mn的摩尔比为0.2... 碱金属作为助剂,能够调变催化剂的电子和结构性能,从而改善催化剂的活性。本工作中,我们研究了碱金属K的添加对Mn Ox/Ce0.65Zr0.35O2催化剂氧化甲苯的性能影响。结果表明,掺杂碱金属K可以明显提高催化剂的催化活性;当K与Mn的摩尔比为0.2时,催化剂Mn/Ce0.65Zr0.35O2-K-0.2表现出最好的活性。在体积空速为12000 h-1时,其完全转化温度T90为242°C。同时采用X射线粉末衍射、紫外/可见拉曼、程序升温还原与吸脱附、光电子能谱及红外原位等表征技术研究K的添加对催化剂Mn Ox/Ce0.65Zr0.35O2性能影响。结果表明,适量K的添加可以提高催化剂的氧化还原性能,增加催化剂表面缺陷位并提高晶格氧的移动性,同时增加了催化剂表面活性氧物种浓度,从而提高催化剂催化氧化甲苯的能力。 展开更多
关键词 甲苯 催化氧化 铈锆固溶体 锰氧化物
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焙烧温度对Ce0.65Zr0.35O_2储氧材料性能的影响 认领 引用 被引量:8
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作者 赵明 余全伟 +3 位作者 蔡黎 龚茂初 刘志敏 陈耀强 《功能材料》 EI CAS 北大核心 2008年第5期793-796,共4页
用共沉淀法制备了Ce0.65Zr0.35O2氧化物,对不同温度处理后的样品进行了XRD、Raman、BET和储氧量(OSC)的表征。并考察了不同温度焙烧后的氧化物对单钯催化剂三效性能的影响。结果表明,焙烧温度的不同,样品具有不同的织构性能,但该样品的... 用共沉淀法制备了Ce0.65Zr0.35O2氧化物,对不同温度处理后的样品进行了XRD、Raman、BET和储氧量(OSC)的表征。并考察了不同温度焙烧后的氧化物对单钯催化剂三效性能的影响。结果表明,焙烧温度的不同,样品具有不同的织构性能,但该样品的晶相结构稳定,老化前后均为立方相的铈锆固溶体,经1000℃焙烧后未出现相分离,说明该氧化物具有良好的热稳定性能;活性测试结果表明,不同焙烧温度的载体对催化活性影响较大,并以700℃焙烧后的氧化物为载体的催化剂具有最好的三效性能。 展开更多
关键词 焙烧温度 Ce0.65Zr0.35O2储氧材料 结构 织构性能 Pb催化剂
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Preparation of Ce0.65Zr0.35O_2 by co-precipitation: The role of hydrogen peroxide 认领 引用 被引量:5
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作者 黄利华 陈山虎 +2 位作者 朱艺 龚茂初 陈耀强 《Journal of Rare Earths》 SCIE EI CAS CSCD 2013年第5期461-469,共9页
The effect of H2O2 on the properties of Ce0.65Zr0.35O2 a mixed aqueous solution of ammonia and was explored by treating cerium nitrate and zirconium nitrate with in the presence/absence of H2O2. The resultant products... The effect of H2O2 on the properties of Ce0.65Zr0.35O2 a mixed aqueous solution of ammonia and was explored by treating cerium nitrate and zirconium nitrate with in the presence/absence of H2O2. The resultant products were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption/desorption, oxygen storage capacity (OSC) and H2- reduction (H2-TPR). The presence of H2O2 was found to have profound effect on powder properties such as surface area, crystallite size of the samples. It was also shown that the addition of H2O2 favored the incorporation of Zr4+ into CeO2 lattice, which facilitated the formation of CeO2-ZrO2 solid solution, and enhanced the thermal stability of the samples. OSC and H2-TPR studies indicated that the use of H2O2 enhanced the OSC and redox properties. Catalytic activity tests showed that as a support, the Ce0.65Zr0.35O2 prepared in the presence of H2O2 was more suitable for three-way catalyst. The corresponding Pd-only three-way catalyst demonstrated outstanding performance: wide air to fuel operation window, low light-off and total conversion temperature for the conversion of C3H8, NO and CO. 展开更多
关键词 solid solution H2O2 oxygen storage capacity three-way catalysts Ce0.65Zr0.35O2 rare earths
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储氧材料制备过程中的结构及织构变化 认领 引用 被引量:5
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作者 赵明 郭家秀 +5 位作者 刘萍 房华 蔡黎 毛小波 龚茂初 陈耀强 《无机化学学报》 SCIE CAS 北大核心 2006年第6期1123-1126,共4页
Ce0.65Zr0.35O2 solid solution was prepared by co-precipitation method and characterized by X-ray diffraction (XRD), Raman spectra, BET, oxygen storage capacity (OSC) and temperature-programmed reduction measurements (... Ce0.65Zr0.35O2 solid solution was prepared by co-precipitation method and characterized by X-ray diffraction (XRD), Raman spectra, BET, oxygen storage capacity (OSC) and temperature-programmed reduction measurements (H2-TPR) after calcination at 100 ℃, 300 ℃, 600 ℃, and 1 000 ℃. The results showed that the precipitation was a crystalline of fluorite structure, and in the process of the precipitation transformation into Ce0.65Zr0.35O2 solid solution, the fluorite structure of the precipitation kept unchanged. The samples had different BET surface areas and OSC at different temperatures, but they held the performance of stable structure. After 1 000 ℃, there didn′t appear the other crystalline phase. So the samples prepared by co-precipitation method had excellent texture and higher thermal stability. 展开更多
关键词 共沉淀 Ce0.65Zr0.35O2氧化物 同晶转化 织构 结构
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不同载体对甲醇分解钯催化剂性能的影响 认领 引用 被引量:4
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作者 赵明 王海容 +3 位作者 蔡黎 朱艺 龚茂初 陈耀强 《稀有金属材料与工程》 SCIE EI CAS 北大核心 2010年第3期519-522,共4页
用浸渍法制备了Pd/γ-Al2O3和Pd/Ce0.65Zr0.35O22种甲醇分解催化剂。采用XRD,NH3-TPD(NH3-Temperature-Programmed Desorption),XPS及H2-TPR(H2-Temperature-Programmed-Redution)等手段对2种催化剂的结构和性能进行表征,并考察了催化... 用浸渍法制备了Pd/γ-Al2O3和Pd/Ce0.65Zr0.35O22种甲醇分解催化剂。采用XRD,NH3-TPD(NH3-Temperature-Programmed Desorption),XPS及H2-TPR(H2-Temperature-Programmed-Redution)等手段对2种催化剂的结构和性能进行表征,并考察了催化剂上甲醇低温分解的活性。结果表明,Pd/Ce0.65Zr0.35O2催化剂具有较弱的表面酸性及良好的低温还原性能;XPS结果表明2种催化剂中的Pd均以氧化态形式存在,并且Pd在Ce0.65Zr0.35O2固溶体上呈高度分散状态,Pd与Ce间具有较强的相互作用。结合活性考察可知,Pd+的存在有利于甲醇的分解。Pd/Ce0.65Zr0.35O2催化剂具有高的催化活性,220℃时甲醇转化率接近100%。 展开更多
关键词 γ-Al2O3 Ce0.65Zr0.35O2 Pd催化剂 甲醇分解
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(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2Zr2O7:A novel high-entropy ceramic with low thermal conductivity and sluggish grain growth rate 认领 引用 被引量:63
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作者 Zifan Zhao Huimin Xiang +2 位作者 Fu-Zhi Dai Zhijian Peng Yanchun Zhou 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2019年第11期2647-2651,共5页
Fine grains and slow grain growth rate are beneficial to preventing the thermal stress-induced cracking and thermal conductivity increase of thermal barrier coatings.Inspired by the sluggish diffusion effect of high-e... Fine grains and slow grain growth rate are beneficial to preventing the thermal stress-induced cracking and thermal conductivity increase of thermal barrier coatings.Inspired by the sluggish diffusion effect of high-entropy materials,a novel high-entropy(HE)rare-earth zirconate solid solution(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2 Zr2 O7 was designed and successfully synthesized in this work.The as-synthesized(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2 Zr2 O7 is phase-pure with homogeneous rare-earth element distribution.The thermal conductivity of as-synthesized(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2 Zr2 O7 at room temperature is as low as 0.76 W m^-1 K^-1.Moreover,after being heated at 1500℃for 1-18 h,the average grain size of(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2 Zr2 O7 only increases from 1.69μm to 3.92μm,while the average grain size of La2Zr2O7 increases from 1.96μm to 8.89μm.Low thermal conductivity and sluggish grain growth rate indicate that high-entropy(La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2Zr2O7 is suitable for application as a thermal barrier coating material and it may possess good thermal stress-induced cracking resistance. 展开更多
关键词 (La0.2Ce0.2Nd0.2Sm0.2Eu0.2)2Zr2O7 High-entropy ceramics Thermal barrier coatings Slow grain growth rate
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La_2(Zr0.7Ce0.3)_2O_7——新型高温热障涂层 认领 引用 被引量:18
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作者 牟仁德 许振华 +2 位作者 贺世美 何利民 曹学强 《材料工程》 EI CAS 北大核心 2009年第7期67-71,78,共5页
采用电子束物理气相沉积技术(EB-PVD)制备了新型La2(Zr0.7Ce0.3)2O7(LZ7C3)热障涂层。研究了涂层的组分、显微结构、表面和横截面形貌以及恒温氧化行为。结果表明:涂层中La2O3/ZrO2/CeO2的相对含量偏离了化学计量比,但X射线衍射(XRD)相... 采用电子束物理气相沉积技术(EB-PVD)制备了新型La2(Zr0.7Ce0.3)2O7(LZ7C3)热障涂层。研究了涂层的组分、显微结构、表面和横截面形貌以及恒温氧化行为。结果表明:涂层中La2O3/ZrO2/CeO2的相对含量偏离了化学计量比,但X射线衍射(XRD)相结构与靶材非常相似。通过CeO2掺杂后,LZ7C3体材料的热膨胀系数比La2Zr2O7(LZ)大;在1100℃恒温氧化890h的条件下,LZ7C3涂层的抗氧化增重性能明显优于传统的Y2O3部分稳定化的ZrO2(8YSZ)涂层。此外,热膨胀不匹配、黏结层氧化和陶瓷涂层内部微观裂纹的出现可能是导致LZ7C3涂层恒温氧化失效的主要原因。 展开更多
关键词 热障涂层 EB-PVD 等温氧化 La2(Zr0.7Ce0.3)2O7
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Co/Ce0.5Zr0.5O2催化剂的制备及甲烷部分氧化制合成气 认领 引用 被引量:16
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作者 余长林 胡久彪 +2 位作者 翁维正 周晓春 陈喜蓉 《燃料化学学报》 CSCD 北大核心 2012年第4期418-423,共6页
利用共沉淀法制备了具有介孔结构的Ce0.5Zr0.5O2固溶体载体,然后浸渍不同质量分数(10%、20%、30%)的活性组分钴,制备了系列Co/Ce0.5Zr0.5O2催化剂。利用N2物理吸附(BET)、X射线粉末衍射(XRD)、H2-程序升温还原(H2-TPR)、扫描电子显微镜(... 利用共沉淀法制备了具有介孔结构的Ce0.5Zr0.5O2固溶体载体,然后浸渍不同质量分数(10%、20%、30%)的活性组分钴,制备了系列Co/Ce0.5Zr0.5O2催化剂。利用N2物理吸附(BET)、X射线粉末衍射(XRD)、H2-程序升温还原(H2-TPR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、程序升温氧化(TPO)和热重(TG)等手段对制备和反应后的催化剂进行了表征,研究了它们对甲烷部分氧化制合成气反应的催化性能。研究结果表明,铈锆固溶体负载的钴比较容易被还原,该系列催化剂具有较高的活性和对H2及CO的选择性,且随Co含量的增加,催化剂的活性和对H2和CO的选择性得到提高的同时,也增强了催化剂的抗积炭性能。 展开更多
关键词 Ce0.5Zr0.5O2固溶体 甲烷部分氧化 合成气
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Promoter of (Ce-Zr)O_2 Solid Solution Modified by Praseodymia in Three-Way Catalysts 认领 引用 被引量:4
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作者 汪文栋 林培琰 +4 位作者 孟明 伏义路 胡天斗 谢亚宁 刘涛 《Journal of Rare Earths》 SCIE EI CAS 2003年第4期430-435,共6页
The three way catalysts (TWCs) promoters (Ce Zr)O 2, (Pr Ce Zr)O 2 and (Pr Zr)O 2 were prepared by sol gel like method. They were characterized by XRD, EXAFS and BET surface area determination. The reduction features ... The three way catalysts (TWCs) promoters (Ce Zr)O 2, (Pr Ce Zr)O 2 and (Pr Zr)O 2 were prepared by sol gel like method. They were characterized by XRD, EXAFS and BET surface area determination. The reduction features of the promoters were measured by temperature programmed reduction (TPR) of H 2 to access the potential for the promoters containing praseodymia as oxygen storage component in three way catalyst. The (Pr Zr)O 2 cubic solid solution is formed at high temperature up to 800 ℃, which makes it more reducible than the (Ce Zr)O 2 solid solution. For the (Pr Ce Zr)O 2 samples, the ternary solid solution plays an important role in the reduction process. The performance of the three way catalysts with fully formulated Pt, Pd and Rh is proceeded by using both light off temperature under a stoichiometric gas composition and the conversion of CO, C 3H 6 and NO under changing air/fuel ratio at a constant reaction temperature 400 ℃ . The results indicate that a small amount of praseodymia doping into (Ce Zr)O 2 favors the light off temperature of C 3H 6 and NO, and all the catalysts containing praseodymia obviously exhibits enhanced width of S value for NO conversion at lean region ( S ≥1.00). 展开更多
关键词 catalytic chemistry praseodymium (Ce Zr)O 2 solid solution three way catalysts rare earths
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Structure and catalytic property of CeO_2-ZrO_2-Fe_2O_3 mixed oxide catalysts for diesel soot combustion: Effect of preparation method 认领 引用 被引量:8
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作者 顾振华 桑秀丽 +1 位作者 王华 李孔斋 《Journal of Rare Earths》 SCIE EI CAS CSCD 2014年第9期817-823,共7页
A series of Ceo.sFeo.30Zr0.20O2 catalysts were prepared by different methods (co-precipitations method, citric acid sol-gel method, impregnation method, physical mixed method, and hydrotherrnal method) and character... A series of Ceo.sFeo.30Zr0.20O2 catalysts were prepared by different methods (co-precipitations method, citric acid sol-gel method, impregnation method, physical mixed method, and hydrotherrnal method) and characterized by X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) and H2-TPR measurements. Potential of the catalysts in the soot oxidation was evaluated in a temperature-programmed oxidation (TPO) apparatus. The results showed that all the Fe3+ and Zr4+ were incor- porated into ceria lattice to form a pure Ce-Fe-Zr-O solid solution for the co-precipitation sample, but two kinds of Fe phases ex- isted in the Ce-Fe-Zr-O catalysts prepared by other methods: Fe3+ incorporated into CeO2 lattice and dispersed Fe2O3 clusters. The free Fe2O3 clusters could improve the activity of catalysts for soot oxidation comparing with the pure Ce-Fe-Zr-O solid solution owing to the synergetic effect between free Fe2O3 and surface oxygen vacancies. In addition, the activity of catalysts strongly relied on the surface reducibility of free Fe2O3 particles. Holding both abundant free Fe2O3 particles and high oxygen vacancy concentration, the hydrothermal Ce0.5Fe0.3Zr0.202 catalyst presented the lowest Ti (251℃, ignition temperature of soot oxidation) and Tm (310 ℃, maximum oxidation rate temperature) for soot combustion (with tight-contact between soot and catalysts) among the five samples. Even after aging at 800 ℃ for 10 h, the Ti and Tm were still relatively low, at 273 and 361 ℃, respectively, indicating high catalytic stability. 展开更多
关键词 Ce0.5Fe0.30Zr0.20O2 mixed oxides soot combustion solid solution interaction hydrothermal method rare earths
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等离子喷涂超高温热障涂层用纳米结构La2(Zr(0.75)Ce(0.25))2O7球形喂料的研究 认领 引用 被引量:8
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作者 周飞飞 刘敏 +2 位作者 邓春明 张小锋 王铀 《表面技术》 EI CAS CSCD 北大核心 2020年第4期98-103,112,共6页
目的通过纳米粉体造粒技术制备出适合热喷涂超高温用纳米结构La2(Zr(0.75)Ce(0.25))2O7球形喂料,进而采用热喷涂方法制备出纳米结构的热障涂层,以满足下一代热障涂层服役温度需求。方法以化学共沉淀法合成的纳米La2(Zr(0.75)Ce(0.25))2O... 目的通过纳米粉体造粒技术制备出适合热喷涂超高温用纳米结构La2(Zr(0.75)Ce(0.25))2O7球形喂料,进而采用热喷涂方法制备出纳米结构的热障涂层,以满足下一代热障涂层服役温度需求。方法以化学共沉淀法合成的纳米La2(Zr(0.75)Ce(0.25))2O7粉末为原料,通过球磨、喷雾干燥及热处理工艺制备出纳米结构的La2(Zr(0.75)Ce(0.25))2O7喂料,进而采用大气等离子喷涂方法制备出纳米结构La2(Zr(0.75)Ce(0.25))2O7热障涂层。利用扫描电镜(SEM)和透射电镜(TEM)对原始纳米粉体、纳米喂料及喷涂态涂层进行显微形貌和组织结构分析。此外,通过电感耦合等离子体原子发射光谱法(ICP-AES)对制备的纳米喂料进行成分分析。结果制备出的纳米结构La2(Zr(0.75)Ce(0.25))2O7喂料表面光滑、呈球形,成分与化学计量比基本一致。相对于原始纳米粉末,喂料晶粒长大并不显著。喷涂态涂层部分晶粒长大,但仍保留纳米结构。结论成功制备出纳米结构La2(Zr(0.75)Ce(0.25))2O7球形喂料及纳米结构热障涂层,有望作为下一代超高温热障涂层材料。 展开更多
关键词 等离子喷涂 超高温 热障涂层 纳米结构 La2(Zr(0.75)Ce(0.25))2O7 球形喂料 造粒
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Ce-Zr-O固溶体的制备和表征 认领 引用 被引量:27
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作者 罗孟飞 林瑞 +2 位作者 陈敏 袁贤鑫 郑小明 《中国稀土学报》 CAS 北大核心 2000年第1期35-37,共3页
采用硝酸盐直接分解法、共沉淀法、苹果酸溶胶 凝胶法和柠檬酸溶胶 凝胶法制备了Ce Zr O复合氧化物并进行了表征。溶胶 凝胶法制得的Ce Zr O为立方的Ce0 .5Zr0 .5O2 复合氧化物 (其中少量具有立方性质的t″相 ) ,而直接分解和共沉淀法... 采用硝酸盐直接分解法、共沉淀法、苹果酸溶胶 凝胶法和柠檬酸溶胶 凝胶法制备了Ce Zr O复合氧化物并进行了表征。溶胶 凝胶法制得的Ce Zr O为立方的Ce0 .5Zr0 .5O2 复合氧化物 (其中少量具有立方性质的t″相 ) ,而直接分解和共沉淀法制得的是由立方Ce0 .8Zr0 .2 O2 和四方Ce0 .2 Zr0 .8O2 固溶体组成的复合氧化物。不同制备方法制得的样品由于物相组成不同 ,还原性能也有较大差别。差热分析和X射线衍射分析结果表明 ,凝胶在燃烧的同时生成了Ce0 .5Zr0 .5O2 固溶体。 展开更多
关键词 固溶体 稀土元素 铈锆氧复合物 催化
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制备条件对Ru/Ce0.8Zr0.2O_2催化剂上CO_2甲烷化反应性能的影响 认领 引用 被引量:7
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作者 李涛 王胜 +1 位作者 高典楠 王树东 《燃料化学学报》 CSCD 北大核心 2014年第12期1440-1446,共7页
采用均相法制得Ce0.8Zr0.2O2载体,并以其为载体等体积浸渍制得一系列负载型Ru催化剂。在0.1 MPa、GHSV为10000 h-1、H2/CO2为3.5(物质的量比)的条件下,对催化剂进行评价。借助TG-DSC、BET、H2-TPR等技术对所制备的载体和催化剂进行表征... 采用均相法制得Ce0.8Zr0.2O2载体,并以其为载体等体积浸渍制得一系列负载型Ru催化剂。在0.1 MPa、GHSV为10000 h-1、H2/CO2为3.5(物质的量比)的条件下,对催化剂进行评价。借助TG-DSC、BET、H2-TPR等技术对所制备的载体和催化剂进行表征,结果表明,500℃焙烧的载体具有适中的比表面积和孔径并形成了Ce-Zr固溶体,与载体形成弱相互作用的Ru能够显著提高催化剂的活性,适宜的还原方式能促进活性组分的均匀分布。采用500℃焙烧的载体浸渍Ru Cl3溶液,干燥后在400℃焙烧,并使用水合肼和H2两次还原后的催化剂活性最高,在290℃时,H2转化率可达到93.57%。 展开更多
关键词 Ru/Ce0.8 Zr0.2 O2 焙烧温度 CO2 甲烷化 负载型催化剂
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Study on methane selective catalytic reduction of NO on Pt/Ce0.67Zr0.33O2and its application 认领 引用 被引量:10
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作者 Zhimin Liu Kangcai Wang +4 位作者 Xiaoyu Zhang Jianli Wang Hongyan Cao Maochu Gong Yaoqiang Chen 《Journal of Natural Gas Chemistry》 2009年第1期66-70,共5页
Monolithic catalysts of Pt/La-Al2O3 and Pt/Ce0.67Zr0.3302 were prepared to investigate methane selective catalytic reduction(SCR)of NO.The results indicate that Pt/Ce0.67Zr0.33O2 shows high activity and both NO and CH... Monolithic catalysts of Pt/La-Al2O3 and Pt/Ce0.67Zr0.3302 were prepared to investigate methane selective catalytic reduction(SCR)of NO.The results indicate that Pt/Ce0.67Zr0.33O2 shows high activity and both NO and CH4 can be converted completely at 450℃.Meanwhile,NO and CH4 can be converted completely when there exists excess oxygen.The Pt/Ce0.67Zr0.33O2 catalyst were further investigated by using methane as reducing agent to SCR NO in a novel equipment which combined the CH4 selective catalytic reduction of NO with methane combustion.The result shows that the catalyst is high active and the novel equipment is very effective.The conversion of NO is above 92%under the conditions used in this work.The prepared burner and catalysts have great potential for application. 展开更多
关键词 Pt/Ce0.67Zr0.33O2 selective catalytic reduction NO catalytic burner application
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Characterization and Preparation of Ce-Zr-O Solid Solution 认领 引用 被引量:2
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作者 罗孟飞 周碧 +3 位作者 林瑞 陈敏 袁贤鑫 郑小明 《Journal of Rare Earths》 SCIE EI CAS 2000年第4期275-278,共4页
Ce Zr O solid solution was prepared by four different methods, i.e., decomposition of nitrate, coprecipiation, hydroxysuainic acid sol gel as well as citrate sol gel, and characterized by using X ray powder diffractio... Ce Zr O solid solution was prepared by four different methods, i.e., decomposition of nitrate, coprecipiation, hydroxysuainic acid sol gel as well as citrate sol gel, and characterized by using X ray powder diffraction, Raman and temperature programmed reduction. The phase composition and the reduction properties of Ce Zr O depend on the preparation method. A cubic Ce 0.5 Zr 0.5 O 2 solid solution can be obtained by using the sol gel method. The Ce Zr O solid solution prepared by using decomposition or coprecipiation was composed of cubic Ce 0.8 Zr 0.2 O 2 and tetragonal Ce 0.2 Zr 0.8 O 2 solid solution. The Ce Zr O solid solution prepared with different methods shows the different reduction properties owing to different phase composition. Results of differential thermal analysis and XRD show that Ce 0.5 Zr 0.5 O 2 solid solution is formed during the decomposition or combustion of the gel. 展开更多
关键词 rare earths Ce 0.5 Zr 0.5 O 2 solid solution X ray powder diffraction Raman temperature programmed reduction
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Catalytic combustion study of soot on Ce0.7Zr0.3O_2 solid solution 认领 引用 被引量:4
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作者 方萍 鲁继青 +1 位作者 肖小燕 罗孟飞 《Journal of Rare Earths》 SCIE EI CAS 2008年第2期250-253,共4页
The Ce0.7Zr0.3O2 solid solution and CeO2 were prepared using the sol-gel method. The phase structure, crystallite sizes and the reducibility of the catalysts were characterized by XRD and H2-TPR techniques. XRD result... The Ce0.7Zr0.3O2 solid solution and CeO2 were prepared using the sol-gel method. The phase structure, crystallite sizes and the reducibility of the catalysts were characterized by XRD and H2-TPR techniques. XRD results indicated that Zr^4+ had replaced part of Ce^4+ to form a fluorite-like solid solution, which was favorable to obtain ultrafine nanoparticles. The ratio of main HE consumption for Ce0.7Zr0.3O2:CeO2 was 4.4:1.0, implying that the solid solution could improve the reducibility compared to the single CeO2. The Ce0.7Zr0.3O2 solid solution catalyst showed a sharp combustion peak at 397 ℃, which was 200 ℃ lower than that of the single soot. The good catalytic activity of the Ce0.7Zr0.3O2 was attributed to the formation of nano-CeO2-based solid solution, which enhanced the reducibility and then improved the combustion activity. As Ce0.7Zr0.3O2 could be easily reduced to Ce0.7Zr0.3O2-x meanwhile, after oxygenation, the Ce0.7Zr0.3O2.x was recovered to Ce0.7Zr0.3O2 completely. A catalytic combustion reaction mechanism was proposed: the Ce0.7Zr0.3O2 was reduced to Ce0.7Zr0.3O2-x by the reaction with carbon and then it was recovered to Ce0.7Zr0.3O2-x by the interaction with O2. 展开更多
关键词 Ce0.7Zr0.3O2 reoxidizing-reducing soot combustion catalytic activity rare earths
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Ce0.8Zr0.2O_2固溶体磨料对ZF7光学玻璃抛光性能的改善 认领 引用 被引量:8
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作者 傅毛生 李永绣 +2 位作者 陈伟凡 危亮华 胡建东 《摩擦学学报(中英文)》 EI CAS 北大核心 2009年第2期180-185,共6页
采用改进的湿固相机械化学反应法制备出超细锆掺杂氧化铈磨料Ce1-xZrxO2(x=0,0.2),运用X射线衍射(XRD)、透射电镜(TEM)等手段表征其物相类型、外观形貌、比表面积、粒度、表面电位等物理性质,通过测定抛光速率和观察表面的微观形貌考察... 采用改进的湿固相机械化学反应法制备出超细锆掺杂氧化铈磨料Ce1-xZrxO2(x=0,0.2),运用X射线衍射(XRD)、透射电镜(TEM)等手段表征其物相类型、外观形貌、比表面积、粒度、表面电位等物理性质,通过测定抛光速率和观察表面的微观形貌考察它们对ZF7光学玻璃的抛光性能影响.结果表明,Ce0.8Zr0.2O2固溶体磨料对ZF7光学玻璃抛光性能比纯CeO2磨料有明显的提高,抛光速率达到463 nm/min,5.0μm×5.0μm的范围内微观表面粗糙度Ra值达到1.054 nm,而纯CeO2磨料的抛光速率只有292 nm/min,Ra值却增大到1.441 nm.Ce0.8Zr0.2O2固溶体的抛光速率的明显增大和表面粗糙度Ra的下降主要与其负表面电位的增大和颗粒尺寸、粒度的减小密切相关. 展开更多
关键词 湿固相机械化学反应法 Ce0.8Zr0.2O2固溶体 化学机械抛光 ZF7光学玻璃
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Effect of PdOx structure properties on catalytic performance of Pd/Ce0.67Zr0.33O2 catalyst for CO,HC and NOx elimination 认领 引用 被引量:4
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作者 Ting Wang Xiaolin Guo +1 位作者 Siyu Lin Renxian Zhou 《Journal of Rare Earths》 SCIE EI CAS CSCD 2019年第7期706-713,共8页
Pd/Ce0.67Zr0.33O2 catalyst was pretreated in different atmosphere respectively, and characterized by CO chemical adsorption, XPS, HR-TEM, H2-TPR, Raman, OSC and in situ DRIFTS to investigate the effect of the structur... Pd/Ce0.67Zr0.33O2 catalyst was pretreated in different atmosphere respectively, and characterized by CO chemical adsorption, XPS, HR-TEM, H2-TPR, Raman, OSC and in situ DRIFTS to investigate the effect of the structure properties of PdOx species on the catalytic performance for CO, HC and NOx elimination. The results show that Pd/CZ catalyst pretreated in air atmosphere has higher oxidation activity of HC due to having high Pd dispersion and strong interaction between PdOx and CZ support. Pd/CZ-H catalyst pretreated in reducing atmosphere exhibits better catalytic performance of NOx elimination because of having relatively big Pd particle size, more Pd species in metallic state and higher concentration of oxygen vacancies. While for the Pd/CZ-RG catalyst pretreated in reactant atmosphere, strong adsorption of HC species on the surface of catalysts would lead to a part of active sites being covered, which inhibits HC and NO conversions. 展开更多
关键词 Pretreatment atmosphere Structure properties of PdOx species Pd/Ce0.67Zr0.33O2 catalyst TWCs performance Rare earths
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掺杂Ce/Zr对γ-Al_2O_3(110)表面的影响 认领 引用 被引量:4
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作者 杨涛 曹蕃 +6 位作者 刘利军 李海峰 卿梦霞 苏胜 胡松 汪一 向军 《燃烧科学与技术》 CAS CSCD 北大核心 2017年第6期542-546,共5页
采用密度泛函理论(DFT)计算了掺杂Ce/Zr时γ-Al_2O_3(110)表面能量的变化,探讨了其对γ-Al_2O_3(110)表面的影响.结果表明,掺杂Ce/Zr有利于g-Al_2O_3(110)表面氧空穴位的形成,从而促进氧分子的吸附和分解,增加表面活性氧数量.掺杂Ce可促... 采用密度泛函理论(DFT)计算了掺杂Ce/Zr时γ-Al_2O_3(110)表面能量的变化,探讨了其对γ-Al_2O_3(110)表面的影响.结果表明,掺杂Ce/Zr有利于g-Al_2O_3(110)表面氧空穴位的形成,从而促进氧分子的吸附和分解,增加表面活性氧数量.掺杂Ce可促进g-Al_2O_3(110)表面对NO的吸附,但不利于对NH3的吸附.掺杂Zr可促进g-Al_2O_3(110)表面对NO和NH3的吸附. 展开更多
关键词 密度泛函理论(DFT) 选择性催化还原催化剂 γ-Al2O3 Ce Zr
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